mrgee2jz Posted November 22, 2010 Author Share Posted November 22, 2010 What i was thinking is quite complicated but im pritty sure it will give you enough extra power to be worth the time and effort, its a mix of designs but may proove the most effective 1. route both breather hoses to a catch tank 2. at the bottom of the catch tank route to the exhaust via the 1 way valve, therefore no emptying, then test for vacuum up to redline using a gauge, if not sufficient or too much vac is created then... a. if too much is created, use a 1 way bleed valve or similar to relieve excess vac b. if not enough vac is created at higher rpm/boost then install a vacuum pump, using a bmw cold start emission air pump to create sufficient vacbut controlled by a regulator or valve to keep vac at a constant rate. can also ve use with a few one way valves... Quote Link to comment Share on other sites More sharing options...
JamieP Posted November 22, 2010 Share Posted November 22, 2010 If I was you I would rebuild the engine, if it's breathing so heavy you are getting oil it has a problem, only ever seen a bit of water condensation in mine. Quote Link to comment Share on other sites More sharing options...
dandan Posted November 22, 2010 Share Posted November 22, 2010 (edited) If I was you I would rebuild the engine, if it's breathing so heavy you are getting oil it has a problem, only ever seen a bit of water condensation in mine. Same here, except mine generally seems to go out the exhaust as mucho condensation Catch tank has never had more than a hint of oil residue in any trapped water. Edited November 22, 2010 by dandan (see edit history) Quote Link to comment Share on other sites More sharing options...
hodge Posted November 22, 2010 Share Posted November 22, 2010 My catch tank on my blue supra only ever saw totally clear water in it, it did stink of a petroly smell but no oil what so ever. Quote Link to comment Share on other sites More sharing options...
jevansio Posted November 22, 2010 Share Posted November 22, 2010 (edited) What i was thinking is quite complicated but im pritty sure it will give you enough extra power to be worth the time and effort, its a mix of designs but may proove the most effective 1. route both breather hoses to a catch tank 2. at the bottom of the catch tank route to the exhaust via the 1 way valve, therefore no emptying, then test for vacuum up to redline using a gauge, if not sufficient or too much vac is created then... a. if too much is created, use a 1 way bleed valve or similar to relieve excess vac b. if not enough vac is created at higher rpm/boost then install a vacuum pump, using a bmw cold start emission air pump to create sufficient vacbut controlled by a regulator or valve to keep vac at a constant rate. can also ve use with a few one way valves... You're massively overcomplicating things. IMHO there is no way any amount of intake/exhaust pipes going to create any sort of vacuum in the crankcase, they will at best evacuate any pressure in there so it's ambient, maybe a tadge more. Adding a pump will complicate things further. I had a oneway valve in my setup and within weeks it had failed. IMHO simple is best. Pumps and one way valves makes me shudder now. My current plan is to vent both -10 fittings straight to the back of the car, no catch tank, no plumbing into intake/exhaust, no oneway valves, nice and simple Edited November 22, 2010 by jevansio (see edit history) Quote Link to comment Share on other sites More sharing options...
johnny g Posted November 22, 2010 Share Posted November 22, 2010 My current plan is to vent both -10 fittings straight to the back of the car, no catch tank, no plumbing into intake/exhaust, no oneway valves, nice and simple Am interested in this, Jay. Are you just taking the -10 fitting, then running the hose to the end of the car? Quote Link to comment Share on other sites More sharing options...
dandan Posted November 22, 2010 Share Posted November 22, 2010 (edited) I had a oneway valve in my setup and within weeks it had failed. IMHO simple is best. Pumps and one way valves makes me shudder now. My two one way valves to the exhaust have been in place for something like 6000miles and 9 months and are still in good shape and working fine. I've now got a good pressure transducer feed into the Syvecs (currently moitoring exhaust manifold pressure) but I could easily swap that out for an accurate measure of my catch tank pressure once I get a bit of info from Ryan. I can't comment on actual vacuum levels at the mo other than to say if I take the plug off the tank at idle a playing card will easily stick to the face Edit: Just to be clear, I'm not suggesting the exhaust setup is best here. I don't have enough info to say for definite but it certainly seems to be working great for me at the moment. I will make a new thread when I get some vacuum (or maybe not vacuum) readings. Edited November 22, 2010 by dandan (see edit history) Quote Link to comment Share on other sites More sharing options...
jevansio Posted November 22, 2010 Share Posted November 22, 2010 @ Johnny - yip exactly that @ Dan I think the difference is your valves are designed to be in the exhaust, I used some aeromotive -8 one way valves which, although it didn't say, are prolly suited to fuel/liquid and not designed to be passing this gassy type substance I do think when you come to doing your tests you will find the amount of vacuum you measure is negligible. Do i not recall you posting some results before where you hooked up a gauge but believed the gauge to be faulty as it measured basically ambient? If I'm right I bet that was working all along. I had 2 x -10an lines hooked straight into the intake and it failed to pull any measurable vacuum at any point from idle to WOT. Bear in mind here I'm talking 8 inMg as being decent, I would say it pulled a couple mmMg at best. I have no idea how much vacuum an exhaust flow can generate, but I'm guessing if a flow of air a T67 @ 1.5 BAR is sucking isn't enough to pull a vacuum a couple of +ve pressure exhaust flows aren't going to add that much extra? Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted November 22, 2010 Author Share Posted November 22, 2010 If I was you I would rebuild the engine, if it's breathing so heavy you are getting oil it has a problem, only ever seen a bit of water condensation in mine. Im exagerating things a bit here, its not exactly breathing heavy and its only just been run in, built by myself, all rings gaps are perfect and runs like a dream, i ran it without any pipes on it last night @ full boost with harldy anything contaminating the engine bay, but i wanted to remove any possibilties of any oil getting into the intake and intercoolers while helping the engine run more efficiently, creating more power and not having to worry about blowing any crank seals, not that its previously done this Quote Link to comment Share on other sites More sharing options...
Digsy Posted November 22, 2010 Share Posted November 22, 2010 I only read this thread today. Sorry to rewind a bit but in this and other threads on breather systems I'm seeing a lot of references to power gains from running negative crankcase pressure. Leaving aside combustion instability caused by excessive oil carry over, which is a seperate thing, can someone explian to me what the mechanism for increased power simply by increasing the crankcase depression is? Quote Link to comment Share on other sites More sharing options...
jevansio Posted November 22, 2010 Share Posted November 22, 2010 I only read this thread today. Sorry to rewind a bit but in this and other threads on breather systems I'm seeing a lot of references to power gains from running negative crankcase pressure. Leaving aside combustion instability caused by excessive oil carry over, which is a seperate thing, can someone explian to me what the mechanism for increased power simply by increasing the crankcase depression is? Pretty sure when I read on it it was explained as promoted better ring seal, and reduced pumping losses Quote Link to comment Share on other sites More sharing options...
Digsy Posted November 22, 2010 Share Posted November 22, 2010 Better ring seal for a lower tangential load I can understand the physics of at least, as ring pack friction is a big contributor to total engine friction but I'm wondering what the numbers would look like and how big the gains would be. Reduced pumping losses I can't understand because any help offered to the decsending pistons would be cancelled out by opposing the rising pistons. Unless lowering the pressure inside the crankcase somehow helps inter-bay breathing and reduces windage losses. I'll admit to not being 100% up on what is done on race and drag engines, but I'm just wondering if there hasn't been some confusion with crankcase scavenging in a dry sump system somewhere along the line. I can see how a dry sump system would be more effective in removing the oil suspended in the crankcase and help reduce windage losses, but this would be a system where the gas/oil inside the crankcase was removed, the oil seperated out, and the gas then returned to the crankcase, rather than a system where the crankcase pressure was simply lowered. Incidentally, the 8inHg depression you are aiming for is an order of magnitude higher than is usual for a road engine. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted November 22, 2010 Share Posted November 22, 2010 (edited) I wood run bigger than -10, they look big from the outside but if you take a look at the ID of the fittings/hose its no bigger than the standard pipework. Best to go up to 2x -12 or bigger like we've done on Steve L's car which were about 20mm )off the top my head). On both our Time Attack cars we run them into catch tanks with a big breather filter on the tank, works a treat. Edited November 22, 2010 by Paul Whiffin (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 23, 2010 Share Posted November 23, 2010 Just run the two hoses straight into a catch can, but make SURE the catch can also has free ventilation to atmosphere to at least match the area of the openings of the two breather hoses. Here's my set up on my Skyline, -12 hoeses though. I am not into bling, or spending money needlessly, so it may not be to everyone's taste but works fine and cost nothing. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted November 23, 2010 Share Posted November 23, 2010 Here's a picture of my setup Quote Link to comment Share on other sites More sharing options...
hodge Posted November 23, 2010 Share Posted November 23, 2010 Just run the two hoses straight into a catch can, but make SURE the catch can also has free ventilation to atmosphere to at least match the area of the openings of the two breather hoses. Here's my set up on my Skyline, -12 hoeses though. I am not into bling, or spending money needlessly, so it may not be to everyone's taste but works fine and cost nothing. Chris that made me smile lol. Quote Link to comment Share on other sites More sharing options...
hodge Posted November 23, 2010 Share Posted November 23, 2010 Here's a picture of my setup Paul where does the small hose go next to the filter that runs down next to the plenum. Quote Link to comment Share on other sites More sharing options...
dandan Posted November 23, 2010 Share Posted November 23, 2010 @ Dan I think the difference is your valves are designed to be in the exhaust, I used some aeromotive -8 one way valves which, although it didn't say, are prolly suited to fuel/liquid and not designed to be passing this gassy type substance I do think when you come to doing your tests you will find the amount of vacuum you measure is negligible. Do i not recall you posting some results before where you hooked up a gauge but believed the gauge to be faulty as it measured basically ambient? If I'm right I bet that was working all along. I had 2 x -10an lines hooked straight into the intake and it failed to pull any measurable vacuum at any point from idle to WOT. Bear in mind here I'm talking 8 inMg as being decent, I would say it pulled a couple mmMg at best. I have no idea how much vacuum an exhaust flow can generate, but I'm guessing if a flow of air a T67 @ 1.5 BAR is sucking isn't enough to pull a vacuum a couple of +ve pressure exhaust flows aren't going to add that much extra? Sorry Jay I didn't see this. My gauge was knackered and locked solid so no amount of vacuum would have budged it loose. I'll post up when I have the new transducer hooked up. Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted November 23, 2010 Share Posted November 23, 2010 Paul where does the small hose go next to the filter that runs down next to the plenum. You mean the 2 braided hoses? If so thats the power steering, the catch tank and power steering tank are all in one unit. Quote Link to comment Share on other sites More sharing options...
jevansio Posted November 23, 2010 Share Posted November 23, 2010 Better ring seal for a lower tangential load I can understand the physics of at least, as ring pack friction is a big contributor to total engine friction but I'm wondering what the numbers would look like and how big the gains would be. Reduced pumping losses I can't understand because any help offered to the decsending pistons would be cancelled out by opposing the rising pistons. Unless lowering the pressure inside the crankcase somehow helps inter-bay breathing and reduces windage losses. I'll admit to not being 100% up on what is done on race and drag engines, but I'm just wondering if there hasn't been some confusion with crankcase scavenging in a dry sump system somewhere along the line. I can see how a dry sump system would be more effective in removing the oil suspended in the crankcase and help reduce windage losses, but this would be a system where the gas/oil inside the crankcase was removed, the oil seperated out, and the gas then returned to the crankcase, rather than a system where the crankcase pressure was simply lowered. Incidentally, the 8inHg depression you are aiming for is an order of magnitude higher than is usual for a road engine. I was sceptical of it too, so did a lot of reading on it. The 8inHg is a figure quoted on many of the articles i read WRT drag racing, and after my experiments is only reachable with a dedicated vacuum pump, something which may be OK for a drag car, but for me and my lightweight fetish seemed pointless. I've give up on it and am now happy to let my pressure just make it's own way out if I give it a big enough hole Quote Link to comment Share on other sites More sharing options...
hodge Posted November 23, 2010 Share Posted November 23, 2010 You mean the 2 braided hoses? If so thats the power steering, the catch tank and power steering tank are all in one unit. What a great idea. For someone who's looking at de-cluttering that's an essential I recon. Quote Link to comment Share on other sites More sharing options...
DARETT Posted November 23, 2010 Share Posted November 23, 2010 On the note of Darrets car, (sorry Darret) him claiming to be the fastest standing mile Supra in Europe is just wrong imo, his car was built and raced in USA, im sure it could do well in the UK but he will have to change his setup with our noise restrictions and race it in Europe to claim the title, maybe even drive it himself. and fastest RHD supra in the world? i wonder if mine is the fastest with a pair of fluffy dice? You have a point my man, I was actually registered to drive on the day, and was registered to next but we only had 2 runs on Saturday and had to leave to get it to the port in time... Richard's crash kinda messed it up a little but it's coming back here to compete and of course with me driving TBH it's gonna be difficult for a decent mile run in the UK with the noise regs, but I spoke to Cody about it and he may have a way of getting it through so we'll wait and see on that.. Even if it loses a few hundred bhp it "should" be over 200 pretty easily, especially with the nice cold air we have here Otherwise the car is a UK based car. Most of the parts we build our cars with are from the states anyhow, so where it's built is relative imo. I'm actually still using the Whifbitz race head. Alot of people buy shortblocks ready made from the US anyhow. I think ALL the big power cars apart from Paul's are running Turbo kits from abroad as well. So it is really relative when it comes to what was bought where etc... Worst comes to worst the drag records will be made in the UK Jamie I'm sure yours is the fastest with a pair of fluffy dice and probably fastest WB Sorry for the OT, you can go back on topic now Quote Link to comment Share on other sites More sharing options...
JamieP Posted November 23, 2010 Share Posted November 23, 2010 My point is you can't claim to be the fastest standing mile supra in Europe when the car has never done a standing mile in Europe. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 23, 2010 Share Posted November 23, 2010 I am shamed, I think I'll upgrade to an old synthetic oil container, rather than that el cheapo mower oil one Very swish Paul! Quote Link to comment Share on other sites More sharing options...
Kirk Posted November 23, 2010 Share Posted November 23, 2010 Talk about spare no expense chris Quote Link to comment Share on other sites More sharing options...
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